Persons who suffer from mucus-producing respiratory conditions that result in large amounts of mucus being produced in the lungs often require assistance in the removal of these secretions. If these secretions are allowed to remain in the lungs, airway obstruction occurs resulting in poor oxygenation and possible pneumonia and/or death. One of the clinically recognized treatments for this condition is a technique known as positive expiratory pressure therapy or PEP. With PEP therapy, a patient exhales against a resistance to generate expiratory pressure at a substantially constant rate of flow. Prescribed expiratory pressures are generally in the range of 10-20 cm of H2O, although other pressure ranges and pressures can be used, with a preferred flow rate of between 10-25 liters per minute.
In the use of PEP therapy, a patient breaths through an orifice restrictor to generate a positive pressure in the lungs during exhalation, with the pressure falling to zero at the end of the exhalation. By selection of the proper-sized orifice, a given pressure is determined for the exhalation flow rate generated by an individual patient. This extended, substantially constant, flow of elevated-pressure exhalation has been shown to be effective for moving secretions trapped in the lungs to the larger airways where the secretions can then be removed through coughing. It has also been found that in the treatment of patients having chronic obstructive pulmonary disease (COPD), chronic bronchitis, cystic fibrosis, atelectasis, or other conditions producing retained secretions, treatment with PEP therapy is improved by combining positive expiratory pressure therapy with airway oscillation and intermittent air-flow acceleration. To this end hand-held, single patient multi-use, positive expiratory pressure respiratory therapy devices have been developed such as those of U.S. Pat. No. 6,581,598, “POSITIVE EXPIRATORY PRESSURE DEVICE”, and U.S. Pat. No. 7,059,324, “POSITIVE EXPIRATORY PRESSURE DEVICE”.
The devices of the referenced patents have accomplished their desired objectives, and, accordingly, it has become desirable to incorporate such PEP and COPD therapies with a medicated aerosol drug delivery system.